Folding knife



FIG. 1 is a perspective view of a folding knife showing my new design, wherein the blade is in the closed position;

FIG. 2 is a rear elevation view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a right side elevation view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a left side elevation view thereof.

The broken lines depict portions of the folding knife in which the design is embodied that are not considered part of the claimed design. 

CLAIM I claim the ornamental design for a folding knife, as shown and described. 